Arcetri Technical Reports 15/1994

Silicon Echelle Grisms

E. Oliva

Osservatorio Astrofisico di Arcetri

Abstract

The performances of silicon grisms with chemically etched gratings are analyzed and discussed. Simple relationships defining the crucial parameters (resolving power, anamorphic magnification etc.) are derived. It is shown that surprisingly high throughput and resolving powers (7500 with a 1" slit) can be achieved with the IR instrument for the Galileo telescope (TNG) using a Si echelle grism whose manufacturing is within presently available technology. Simulated cross-dispersed spectra are presented.